Hi Jon, I am now learning that mandolintab uses the code formerly used by folkinfo, and you are the programmer. Correct?

If I am not mistaken, all "front end code" runs in the user's browser, never on mandolintab. You probably mean "the front end code as created by mandolintab", which seems to differ from what you call "Simon's front end code" that runs alright on your own machine. You call it "my own local server" but seem to use it as a "client" (is that the same as "front end"?).

In other words: if you have a front end that works correctly with the existing mandolintab.net web server script, it should be possible to modify it step-by-step to meet Simon's present requirements. You will probably find some subtle error that may have been tolerated by an older version of PHP. No redesign should be necessary.

Sorry that I cannot be more specific, because although I have been successful in some easy JavaScript programming, I am by no means an expert.